Optical scanners for stimulation of target samples and for detection of the resulting signal radiation emerging from the samples are used in many experimental formats. Optical scanners having movable scan heads are particularly useful for variable field size. However, many existing scanners, including those with movable scan heads, are limited with respect to scan speed because of their numerous components and the high mass of their optical assemblies. It is desirable to increase scan speed without compromising resolution in order to scan many samples in a short period of time.
A wide variety of scan formats is necessary for many research and diagnostic applications. For example, emerging formats include the scanning of large gels containing fluorescent labels, and the scanning of miniature chips or membranes supporting minute samples. In addition to the variability desired with respect to scan formats, versatility with respect to types of optical analysis is extremely important. Analysis of samples based on storage phosphor emission, fluorescent, reflected, and transmitted light may be necessary. Space and cost considerations dictate the use of instruments allowing analysis in more than one of these modalities.
Because these various optical scanning modalities generally require exciting or stimulating light of a unique wavelength and collection and detection optics capable of separating the various types of returned signals from the target sample, merging many scanning modalities into one optical scanner has been difficult in the past. Providing multiple simultaneous incident wavelengths and subsequently descanning and detecting the coincident sample emission generally results in complex and expensive instruments and difficult analysis. For example, see U.S. Pat. No. 5,304,810 to Amos.
It is therefore an object of the present invention to provide a compact, versatile optical scanner of simple, lightweight, and low cost design for rapid scanning of target samples according to any of a multiple of scanning modalities.